1221203321321 has 8 divisors (see below), whose sum is σ = 1224666844800. Its totient is φ = 1217743358832.

The previous prime is 1221203321311. The next prime is 1221203321329. The reversal of 1221203321321 is 1231233021221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221203321321 - 2⁶ = 1221203321257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221203321329) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 202646 + ... + 1575903.

It is an arithmetic number, because the mean of its divisors is an integer number (153083355600).

Almost surely, 2^{1221203321321} is an apocalyptic number.

It is an amenable number.

1221203321321 is a deficient number, since it is larger than the sum of its proper divisors (3463523479).

1221203321321 is a wasteful number, since it uses less digits than its factorization.

1221203321321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1780495.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 1221203321321 its reverse (1231233021221), we get a palindrome (2452436342542).

The spelling of 1221203321321 in words is "one trillion, two hundred twenty-one billion, two hundred three million, three hundred twenty-one thousand, three hundred twenty-one".